Proximity‐Induced Valley Polarization and Magnetic Sensing in Two‐Dimensional Magnetic Heterostructures
Kaixuan Zhang, Rui Mei, Yilv Guo, Qian He, Bingyan Ren, Yubo Tian, Lei Gao, Miaoling Lin, Xinfeng Liu, Jun Zhang, Jinlan Wang, Pingheng Tan, Weijie ZhaoABSTRACT
Two‐dimensional magnetic semiconductors integrated into van der Waals heterostructures provide a promising platform for engineering spintronic and valleytronic functionalities through magnetic proximity effects. Here, we construct van der Waals heterostructures formed by ultrathin layered magnetic semiconductor CrSBr and non‐magnetic transition metal dichalcogenides (i.e., monolayer WSe 2 ). Pronounced valley‐contrasting photoluminescence from monolayer WSe 2 emerges within CrSBr/WSe 2 heterostructures, in spite of their intrinsically orthogonal spin alignment. Femtosecond pump‐probe spectroscopy combined with theoretical calculations reveals that this emergent phenomenon originates from MPE‐induced spin canting in WSe 2 and the consequent spin‐selective interlayer electron transfer. Notably, the degree of emergent circular polarization of monolayer WSe 2 is highly sensitive to the layer number or magnetism of CrSBr, indicating that WSe 2 can serve as an atomically thin magnetic sensor. Our results deepen the understanding of magnetic proximity effects in two‐dimensional magnetic heterostructures and provide guidance for designing multifunctional devices for spintronic, valleytronic, and sensing applications.